Begin by gathering all your ingredients for the Peppermint Swirl Fudge. Measure out sweetened condensed milk, white chocolate chips, semi-sweet chocolate chips, peppermint extract, and crushed peppermint candies. Line an 8x8-inch baking dish with parchment paper, allowing some overhang for easy removal later. Set your stove to low heat and gather a medium saucepan and a rubber spatula for smooth mixing.

In the medium saucepan, combine the white chocolate chips and sweetened condensed milk. Heat over low, stirring constantly for about 5 minutes until it melts into a smooth mixture without any lumps.

Once the white chocolate mixture is smooth, promptly remove it from the heat. Add in the peppermint extract and stir well to infuse the fudge with its refreshing flavor. Afterward, divide the mixture in half, pouring half into the prepared baking dish.

Next, in the same saucepan, melt the semi-sweet chocolate chips using the same method as before. Once melted, pour the dark chocolate mixture over the white chocolate layer already in the dish.

To create an eye-catching marbled effect, gently swirl the two layers together with a toothpick or a knife.

Sprinkle crushed peppermint candies generously over the top of the fudge, pressing them lightly into the surface. Cover the baking dish with plastic wrap and refrigerate for about 2 hours or until the fudge is completely set and firm to the touch.

Once the fudge has chilled and firmed up, carefully lift it out of the baking dish using the overhanging parchment paper. Place it on a cutting board and cut into bite-sized squares.